An underground transformer cabin consisting of two units, one inside the other, in which the external unit is designed to support earth pressure, the weight of the covering plate and the stress caused by surface traffic, while the smaller internal unit is designed specifically for the installation of electrical equipment.
It is common knowledge that in cities and large urban areas, the enormous electric power needed and the lack of space, has made it necessary to build an increasing number of underground electric cabins.
To date, these cabins have always been box-shaped, consisting of a single large parallelepiped box made of reinforced concrete with two incorporated or applied air vents for the air flow and exchange in the cabin.
In fact, one of the most important technical specifications for these cabins is the specification requiring continuous and efficient natural ventilation of the cabins, to ensure adequate cooling of the transformer and to avoid the very dangerous formation of water condensation.
To provide adequate ventilation of the cabin, generally, partition panels are used to direct the incoming fresh air towards the base of the transformer, while the outlet openings for the hot air are provided at the top, opposite the inlet openings, in order to provide natural ventilation based on an ascending air current which passes through the electric cabin continuously.